2 * dock.c - ACPI dock station driver
4 * Copyright (C) 2006 Kristen Carlson Accardi <kristen.c.accardi@intel.com>
6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or (at
11 * your option) any later version.
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/types.h>
29 #include <linux/notifier.h>
30 #include <linux/jiffies.h>
31 #include <acpi/acpi_bus.h>
32 #include <acpi/acpi_drivers.h>
34 #define ACPI_DOCK_DRIVER_NAME "ACPI Dock Station Driver"
36 ACPI_MODULE_NAME("dock")
37 MODULE_AUTHOR("Kristen Carlson Accardi");
38 MODULE_DESCRIPTION(ACPI_DOCK_DRIVER_NAME
);
39 MODULE_LICENSE("GPL");
41 static struct atomic_notifier_head dock_notifier_list
;
45 unsigned long last_dock_time
;
49 struct list_head dependent_devices
;
50 struct list_head hotplug_devices
;
53 struct dock_dependent_device
{
54 struct list_head list
;
55 struct list_head hotplug_list
;
57 acpi_notify_handler handler
;
61 #define DOCK_DOCKING 0x00000001
63 #define UNDOCK_EVENT 2
65 static struct dock_station
*dock_station
;
67 /*****************************************************************************
68 * Dock Dependent device functions *
69 *****************************************************************************/
71 * alloc_dock_dependent_device - allocate and init a dependent device
72 * @handle: the acpi_handle of the dependent device
74 * Allocate memory for a dependent device structure for a device referenced
77 static struct dock_dependent_device
*
78 alloc_dock_dependent_device(acpi_handle handle
)
80 struct dock_dependent_device
*dd
;
82 dd
= kzalloc(sizeof(*dd
), GFP_KERNEL
);
85 INIT_LIST_HEAD(&dd
->list
);
86 INIT_LIST_HEAD(&dd
->hotplug_list
);
92 * add_dock_dependent_device - associate a device with the dock station
93 * @ds: The dock station
94 * @dd: The dependent device
96 * Add the dependent device to the dock's dependent device list.
99 add_dock_dependent_device(struct dock_station
*ds
,
100 struct dock_dependent_device
*dd
)
102 spin_lock(&ds
->dd_lock
);
103 list_add_tail(&dd
->list
, &ds
->dependent_devices
);
104 spin_unlock(&ds
->dd_lock
);
108 * dock_add_hotplug_device - associate a hotplug handler with the dock station
109 * @ds: The dock station
110 * @dd: The dependent device struct
112 * Add the dependent device to the dock's hotplug device list
115 dock_add_hotplug_device(struct dock_station
*ds
,
116 struct dock_dependent_device
*dd
)
118 spin_lock(&ds
->hp_lock
);
119 list_add_tail(&dd
->hotplug_list
, &ds
->hotplug_devices
);
120 spin_unlock(&ds
->hp_lock
);
124 * dock_del_hotplug_device - remove a hotplug handler from the dock station
125 * @ds: The dock station
126 * @dd: the dependent device struct
128 * Delete the dependent device from the dock's hotplug device list
131 dock_del_hotplug_device(struct dock_station
*ds
,
132 struct dock_dependent_device
*dd
)
134 spin_lock(&ds
->hp_lock
);
135 list_del(&dd
->hotplug_list
);
136 spin_unlock(&ds
->hp_lock
);
140 * find_dock_dependent_device - get a device dependent on this dock
141 * @ds: the dock station
142 * @handle: the acpi_handle of the device we want
144 * iterate over the dependent device list for this dock. If the
145 * dependent device matches the handle, return.
147 static struct dock_dependent_device
*
148 find_dock_dependent_device(struct dock_station
*ds
, acpi_handle handle
)
150 struct dock_dependent_device
*dd
;
152 spin_lock(&ds
->dd_lock
);
153 list_for_each_entry(dd
, &ds
->dependent_devices
, list
) {
154 if (handle
== dd
->handle
) {
155 spin_unlock(&ds
->dd_lock
);
159 spin_unlock(&ds
->dd_lock
);
163 /*****************************************************************************
165 *****************************************************************************/
167 * is_dock - see if a device is a dock station
168 * @handle: acpi handle of the device
170 * If an acpi object has a _DCK method, then it is by definition a dock
171 * station, so return true.
173 static int is_dock(acpi_handle handle
)
178 status
= acpi_get_handle(handle
, "_DCK", &tmp
);
179 if (ACPI_FAILURE(status
))
185 * is_dock_device - see if a device is on a dock station
186 * @handle: acpi handle of the device
188 * If this device is either the dock station itself,
189 * or is a device dependent on the dock station, then it
192 int is_dock_device(acpi_handle handle
)
197 if (is_dock(handle
) || find_dock_dependent_device(dock_station
, handle
))
203 EXPORT_SYMBOL_GPL(is_dock_device
);
206 * dock_present - see if the dock station is present.
207 * @ds: the dock station
209 * execute the _STA method. note that present does not
210 * imply that we are docked.
212 static int dock_present(struct dock_station
*ds
)
218 status
= acpi_evaluate_integer(ds
->handle
, "_STA", NULL
, &sta
);
219 if (ACPI_SUCCESS(status
) && sta
)
228 * dock_create_acpi_device - add new devices to acpi
229 * @handle - handle of the device to add
231 * This function will create a new acpi_device for the given
232 * handle if one does not exist already. This should cause
233 * acpi to scan for drivers for the given devices, and call
234 * matching driver's add routine.
236 * Returns a pointer to the acpi_device corresponding to the handle.
238 static struct acpi_device
* dock_create_acpi_device(acpi_handle handle
)
240 struct acpi_device
*device
= NULL
;
241 struct acpi_device
*parent_device
;
245 if (acpi_bus_get_device(handle
, &device
)) {
247 * no device created for this object,
248 * so we should create one.
250 acpi_get_parent(handle
, &parent
);
251 if (acpi_bus_get_device(parent
, &parent_device
))
252 parent_device
= NULL
;
254 ret
= acpi_bus_add(&device
, parent_device
, handle
,
255 ACPI_BUS_TYPE_DEVICE
);
257 pr_debug("error adding bus, %x\n",
266 * dock_remove_acpi_device - remove the acpi_device struct from acpi
267 * @handle - the handle of the device to remove
269 * Tell acpi to remove the acpi_device. This should cause any loaded
270 * driver to have it's remove routine called.
272 static void dock_remove_acpi_device(acpi_handle handle
)
274 struct acpi_device
*device
;
277 if (!acpi_bus_get_device(handle
, &device
)) {
278 ret
= acpi_bus_trim(device
, 1);
280 pr_debug("error removing bus, %x\n", -ret
);
286 * hotplug_dock_devices - insert or remove devices on the dock station
287 * @ds: the dock station
288 * @event: either bus check or eject request
290 * Some devices on the dock station need to have drivers called
291 * to perform hotplug operations after a dock event has occurred.
292 * Traverse the list of dock devices that have registered a
293 * hotplug handler, and call the handler.
295 static void hotplug_dock_devices(struct dock_station
*ds
, u32 event
)
297 struct dock_dependent_device
*dd
;
299 spin_lock(&ds
->hp_lock
);
302 * First call driver specific hotplug functions
304 list_for_each_entry(dd
, &ds
->hotplug_devices
, hotplug_list
) {
306 dd
->handler(dd
->handle
, event
, dd
->context
);
310 * Now make sure that an acpi_device is created for each
311 * dependent device, or removed if this is an eject request.
312 * This will cause acpi_drivers to be stopped/started if they
315 list_for_each_entry(dd
, &ds
->dependent_devices
, list
) {
316 if (event
== ACPI_NOTIFY_EJECT_REQUEST
)
317 dock_remove_acpi_device(dd
->handle
);
319 dock_create_acpi_device(dd
->handle
);
321 spin_unlock(&ds
->hp_lock
);
324 static void dock_event(struct dock_station
*ds
, u32 event
, int num
)
327 * we don't do events until someone tells me that
328 * they would like to have them.
333 * eject_dock - respond to a dock eject request
334 * @ds: the dock station
336 * This is called after _DCK is called, to execute the dock station's
339 static void eject_dock(struct dock_station
*ds
)
341 struct acpi_object_list arg_list
;
342 union acpi_object arg
;
346 /* all dock devices should have _EJ0, but check anyway */
347 status
= acpi_get_handle(ds
->handle
, "_EJ0", &tmp
);
348 if (ACPI_FAILURE(status
)) {
349 pr_debug("No _EJ0 support for dock device\n");
354 arg_list
.pointer
= &arg
;
355 arg
.type
= ACPI_TYPE_INTEGER
;
356 arg
.integer
.value
= 1;
358 if (ACPI_FAILURE(acpi_evaluate_object(ds
->handle
, "_EJ0",
360 pr_debug("Failed to evaluate _EJ0!\n");
364 * handle_dock - handle a dock event
365 * @ds: the dock station
366 * @dock: to dock, or undock - that is the question
368 * Execute the _DCK method in response to an acpi event
370 static void handle_dock(struct dock_station
*ds
, int dock
)
373 struct acpi_object_list arg_list
;
374 union acpi_object arg
;
375 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
376 struct acpi_buffer name_buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
377 union acpi_object
*obj
;
379 acpi_get_name(ds
->handle
, ACPI_FULL_PATHNAME
, &name_buffer
);
380 obj
= name_buffer
.pointer
;
382 printk(KERN_INFO PREFIX
"%s\n", dock
? "docking" : "undocking");
384 /* _DCK method has one argument */
386 arg_list
.pointer
= &arg
;
387 arg
.type
= ACPI_TYPE_INTEGER
;
388 arg
.integer
.value
= dock
;
389 status
= acpi_evaluate_object(ds
->handle
, "_DCK", &arg_list
, &buffer
);
390 if (ACPI_FAILURE(status
))
391 pr_debug("%s: failed to execute _DCK\n", obj
->string
.pointer
);
392 kfree(buffer
.pointer
);
393 kfree(name_buffer
.pointer
);
396 static inline void dock(struct dock_station
*ds
)
401 static inline void undock(struct dock_station
*ds
)
406 static inline void begin_dock(struct dock_station
*ds
)
408 ds
->flags
|= DOCK_DOCKING
;
411 static inline void complete_dock(struct dock_station
*ds
)
413 ds
->flags
&= ~(DOCK_DOCKING
);
414 ds
->last_dock_time
= jiffies
;
418 * dock_in_progress - see if we are in the middle of handling a dock event
419 * @ds: the dock station
421 * Sometimes while docking, false dock events can be sent to the driver
422 * because good connections aren't made or some other reason. Ignore these
423 * if we are in the middle of doing something.
425 static int dock_in_progress(struct dock_station
*ds
)
427 if ((ds
->flags
& DOCK_DOCKING
) ||
428 time_before(jiffies
, (ds
->last_dock_time
+ HZ
)))
434 * register_dock_notifier - add yourself to the dock notifier list
435 * @nb: the callers notifier block
437 * If a driver wishes to be notified about dock events, they can
438 * use this function to put a notifier block on the dock notifier list.
439 * this notifier call chain will be called after a dock event, but
440 * before hotplugging any new devices.
442 int register_dock_notifier(struct notifier_block
*nb
)
444 return atomic_notifier_chain_register(&dock_notifier_list
, nb
);
447 EXPORT_SYMBOL_GPL(register_dock_notifier
);
450 * unregister_dock_notifier - remove yourself from the dock notifier list
451 * @nb: the callers notifier block
453 void unregister_dock_notifier(struct notifier_block
*nb
)
455 atomic_notifier_chain_unregister(&dock_notifier_list
, nb
);
458 EXPORT_SYMBOL_GPL(unregister_dock_notifier
);
461 * register_hotplug_dock_device - register a hotplug function
462 * @handle: the handle of the device
463 * @handler: the acpi_notifier_handler to call after docking
464 * @context: device specific data
466 * If a driver would like to perform a hotplug operation after a dock
467 * event, they can register an acpi_notifiy_handler to be called by
468 * the dock driver after _DCK is executed.
471 register_hotplug_dock_device(acpi_handle handle
, acpi_notify_handler handler
,
474 struct dock_dependent_device
*dd
;
480 * make sure this handle is for a device dependent on the dock,
481 * this would include the dock station itself
483 dd
= find_dock_dependent_device(dock_station
, handle
);
485 dd
->handler
= handler
;
486 dd
->context
= context
;
487 dock_add_hotplug_device(dock_station
, dd
);
494 EXPORT_SYMBOL_GPL(register_hotplug_dock_device
);
497 * unregister_hotplug_dock_device - remove yourself from the hotplug list
498 * @handle: the acpi handle of the device
500 void unregister_hotplug_dock_device(acpi_handle handle
)
502 struct dock_dependent_device
*dd
;
507 dd
= find_dock_dependent_device(dock_station
, handle
);
509 dock_del_hotplug_device(dock_station
, dd
);
512 EXPORT_SYMBOL_GPL(unregister_hotplug_dock_device
);
515 * dock_notify - act upon an acpi dock notification
516 * @handle: the dock station handle
517 * @event: the acpi event
518 * @data: our driver data struct
520 * If we are notified to dock, then check to see if the dock is
521 * present and then dock. Notify all drivers of the dock event,
522 * and then hotplug and devices that may need hotplugging. For undock
523 * check to make sure the dock device is still present, then undock
524 * and hotremove all the devices that may need removing.
526 static void dock_notify(acpi_handle handle
, u32 event
, void *data
)
528 struct dock_station
*ds
= (struct dock_station
*)data
;
531 case ACPI_NOTIFY_BUS_CHECK
:
532 if (!dock_in_progress(ds
) && dock_present(ds
)) {
535 if (!dock_present(ds
)) {
536 printk(KERN_ERR PREFIX
"Unable to dock!\n");
539 atomic_notifier_call_chain(&dock_notifier_list
,
541 hotplug_dock_devices(ds
, event
);
543 dock_event(ds
, event
, DOCK_EVENT
);
546 case ACPI_NOTIFY_DEVICE_CHECK
:
548 * According to acpi spec 3.0a, if a DEVICE_CHECK notification
549 * is sent and _DCK is present, it is assumed to mean an
550 * undock request. This notify routine will only be called
551 * for objects defining _DCK, so we will fall through to eject
552 * request here. However, we will pass an eject request through
553 * to the driver who wish to hotplug.
555 case ACPI_NOTIFY_EJECT_REQUEST
:
556 if (!dock_in_progress(ds
) && dock_present(ds
)) {
558 * here we need to generate the undock
559 * event prior to actually doing the undock
560 * so that the device struct still exists.
562 dock_event(ds
, event
, UNDOCK_EVENT
);
563 hotplug_dock_devices(ds
, ACPI_NOTIFY_EJECT_REQUEST
);
566 if (dock_present(ds
))
567 printk(KERN_ERR PREFIX
"Unable to undock!\n");
571 printk(KERN_ERR PREFIX
"Unknown dock event %d\n", event
);
576 * find_dock_devices - find devices on the dock station
577 * @handle: the handle of the device we are examining
579 * @context: the dock station private data
582 * This function is called by acpi_walk_namespace. It will
583 * check to see if an object has an _EJD method. If it does, then it
584 * will see if it is dependent on the dock station.
587 find_dock_devices(acpi_handle handle
, u32 lvl
, void *context
, void **rv
)
591 struct dock_station
*ds
= (struct dock_station
*)context
;
592 struct dock_dependent_device
*dd
;
594 status
= acpi_bus_get_ejd(handle
, &tmp
);
595 if (ACPI_FAILURE(status
))
598 if (tmp
== ds
->handle
) {
599 dd
= alloc_dock_dependent_device(handle
);
601 add_dock_dependent_device(ds
, dd
);
608 * dock_add - add a new dock station
609 * @handle: the dock station handle
611 * allocated and initialize a new dock station device. Find all devices
612 * that are on the dock station, and register for dock event notifications.
614 static int dock_add(acpi_handle handle
)
618 struct dock_dependent_device
*dd
;
620 /* allocate & initialize the dock_station private data */
621 dock_station
= kzalloc(sizeof(*dock_station
), GFP_KERNEL
);
624 dock_station
->handle
= handle
;
625 dock_station
->last_dock_time
= jiffies
- HZ
;
626 INIT_LIST_HEAD(&dock_station
->dependent_devices
);
627 INIT_LIST_HEAD(&dock_station
->hotplug_devices
);
628 spin_lock_init(&dock_station
->dd_lock
);
629 spin_lock_init(&dock_station
->hp_lock
);
630 ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list
);
632 /* Find dependent devices */
633 acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
634 ACPI_UINT32_MAX
, find_dock_devices
, dock_station
,
637 /* add the dock station as a device dependent on itself */
638 dd
= alloc_dock_dependent_device(handle
);
643 add_dock_dependent_device(dock_station
, dd
);
645 /* register for dock events */
646 status
= acpi_install_notify_handler(dock_station
->handle
,
648 dock_notify
, dock_station
);
650 if (ACPI_FAILURE(status
)) {
651 printk(KERN_ERR PREFIX
"Error installing notify handler\n");
656 printk(KERN_INFO PREFIX
"%s \n", ACPI_DOCK_DRIVER_NAME
);
667 * dock_remove - free up resources related to the dock station
669 static int dock_remove(void)
671 struct dock_dependent_device
*dd
, *tmp
;
677 /* remove dependent devices */
678 list_for_each_entry_safe(dd
, tmp
, &dock_station
->dependent_devices
,
682 /* remove dock notify handler */
683 status
= acpi_remove_notify_handler(dock_station
->handle
,
686 if (ACPI_FAILURE(status
))
687 printk(KERN_ERR
"Error removing notify handler\n");
689 /* free dock station memory */
695 * find_dock - look for a dock station
696 * @handle: acpi handle of a device
698 * @context: counter of dock stations found
701 * This is called by acpi_walk_namespace to look for dock stations.
704 find_dock(acpi_handle handle
, u32 lvl
, void *context
, void **rv
)
706 int *count
= (int *)context
;
707 acpi_status status
= AE_OK
;
709 if (is_dock(handle
)) {
710 if (dock_add(handle
) >= 0) {
712 status
= AE_CTRL_TERMINATE
;
718 static int __init
dock_init(void)
724 /* look for a dock station */
725 acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
726 ACPI_UINT32_MAX
, find_dock
, &num
, NULL
);
734 static void __exit
dock_exit(void)
739 postcore_initcall(dock_init
);
740 module_exit(dock_exit
);